The present invention relates to an improved method for cutting, and more particularly to the production of structures by laser cutting layers, or members of film or thin film structures.
Many different structures often require the use of a laser to cut through a membrane, layer, or film, to form a desired formation. One example field that requires the precision and other features of a laser for cutting and forming these formations is the field of microelectromechanical or microelectronic devices. Such devices often require cutting and transporting a delicate thin film structure from a source substrate to a new position on a target substrate. As such, a number of different procedures have been developed for cutting and transporting the thin film formations. For example, low tack adhesives or methods utilizing electrostatic forces have been developed to enable the formation and transportation of the thin film formations.
One known method for machining and attaching a thin film formation is taught in U.S. Pat. No. 6,210,514 to Cheung et al., which is incorporated herein by reference. The process of separating a thin film formation from the layer from which it has been cut, or from an adhesive transportation layer, can often deform, alter, stress, or destroy the thin film structure undesirably. Defects ranging from slight deformation or improper positioning, to major tears or structural deficiencies, can ultimately lead to the failure of the microelectromechanical device into which the thin film formations are placed.
The method of machining an attachment as described in the ""514 patent can be summarized as follows. A thin film is affixed to a low tack polymeric membrane. While positioned on the polymeric membrane, the thin film is machined to define a thin film structure. This thin film structure (or array of thin film structures) is then separated from the polymeric membrane in a mostly deformation-free state. In this manner, various target substrates, including glass, silicon, or printed circuit boards, can be equipped with mostly stress-free thin film structures suitable for use in a wide variety of microelectromechanical or microelectronic devices.
However, structures that are cut through the low tack polymeric membrane still have significant stresses induced by edge contamination resulting from the molten polymeric material, as well as from plastic deformations that arise during delamination of the low tack polymeric membrane from the thin film structure. In addition, a collection of dust results when the laser cuts through the low tack polymeric membrane. This laser cutting dust is a source of additional contamination for the thin film and the microelectromechanical device into which the thin film ultimately mounts. The collection of dust on the thin film can have adverse affects on the functionality of the microelectromechanical or microelectronic devices. Further, once the laser cuts the low tack polymeric membrane during the manufacture of the thin film formation, it is not possible to reuse the low tack polymeric membrane to cut additional thin film structures to form like formations. Reusability would promote reduced costs and improved efficiency.
There is a need in the art for an improved laser cutting method and corresponding apparatus, for manufacturing structures such as thin formations that require laser cutting precision. The present invention is directed toward further solutions to address this need.
In accordance with one example embodiment of the present invention, a method of cutting a member with a laser begins with the step of providing the member. A template is then provided, and adhered to the member. The laser then projects through the template, without intersecting with the template, to cut the member and manufacture the desired formation. The laser does not intersect with, and therefore does not cut, the template structure and cause excess laser cutting dust.
A member, according to one aspect of the present invention, can be in the form of a film having multiple layers. One layer can be a metal layer and another layer can be a polymer layer. For example, the metal layer can be formed of aluminum and the polymer layer can be formed of polyester.
According to another aspect of the present invention, the step of adhering the member to the template can include removably attaching the template having low tack properties to a surface of the member through compression.
According to still another aspect of the present invention, the step of projecting the laser through the template includes directing the laser to pass through the template, without cutting the template, to cut through the member in a pattern corresponding to the template.
In accordance with one embodiment of the present invention, the method further includes the step of transferring the member formations to a removed location. The invention can further include the step of removing the template from the member in a manner such that the template is reusable.
In accordance with still another embodiment of the present invention, a method of cutting a member with a laser is provided. The method includes providing the member, a template, and a base. The member is sandwiched between the base and the template. A laser then projects through the template, without intersecting the template, to cut the member and form one or more member formations.
In accordance with still another embodiment of the present invention, an assemblage includes a member and a template removably adhering to the member. The template is suitable for accommodating a laser in cutting the member.
According to one aspect of the present invention, the member is a film. The film can be formed of multiple layers, such as a metal layer and a polymer layer. The metal layer can be aluminum and the polymer layer can be polyester.
According to another aspect of the present invention, the template can include a layer having a predefined cut out section suitable for accommodating the cutting of the member by the laser.
According to still another aspect of the present invention, the template can have low tack properties and be removably attached to a surface of the member through compression. The template can further be reusable after being removed from the member.